The Navy and Marine Corps will do a full examination of security at bases, as the Navy Yard shooting in Washington, D.C., raises questions about whether America’s military installations are vulnerable and if vetting of civilian contractors is broken.

Secretary of the Navy Ray Mabus on Tuesday directed a four-star admiral and a three-star general to conduct a speedy look by Oct. 1 at whether existing base security policy is being followed in the wake of civilian contractor Aaron Alexis’ bloody rampage.

Authorities say he had the proper government ID to get onto the Navy Yard, which houses several high-level offices, including the commander of naval installations, the Navy’s judge advocate and the home of the chief of naval operations.

How Alexis got into the NAVSEA building is another matter. People familiar with the building say visitors buzz to get in and then must present proper credentials to a guard. Indications are that Alexis shot his way past the guard.

A Pentagon Inspector General’s report released Tuesday criticized the Navy for outsourcing its contractor base access process, starting in 2010 or 2011. The report has been in the works for some time but was made public following a request from House Armed Services Committee Chairman Buck McKeon, R-Palmdale.

The report says that the Navy’s access card system “did not affectively mitigate access control risks” and links the failure to the Navy’s attempt to cut costs. As a result, 52 felons gained routine access to military bases, the report concludes.

In the longer term, the Department of the Navy plans to take a deeper look at whether it should increase security in ways that might fundamentally alter base culture — perhaps even akin to the way airport procedures changed after the September 2001 attacks.

Right now, troops in uniform, retirees, civilian defense workers and some mostly white-collar contractors must have a military-issued photo access card to enter Navy and Marine Corps bases in San Diego County. This is the kind Alexis had, according to a Navy official Tuesday.

Other civilian contractors get a separate access card, the kind criticized in the inspector general report.

In addition, guests invited to retirement ceremonies and other events can often drive on base by simply showing a drivers license.

Some military buildings require an extra credential to get inside. Not many require visitors to pass through a metal detector.

Will any of that change? Navy officials offered few details about their plans on Tuesday. Additionally, Defense Secretary Chuck Hagel has called for a worldwide review of U.S. military base security, and President Barack Obama directed his budget office to conduct a government-wide review of security standards for contractors and employees.

Peter Daly, president of the U.S. Naval Institute and a retired three-star admiral, said getting to zero risk is probably not realistic.

“If you have a person who has already gone through one layer of your defenses because they have the credentials, and they are now an insider with some familiarity with your procedures, and they are armed and they are not concerned about their own life — that is a very daunting scenario to come out with zero losses,” he said.